Under adverse conditions, the following distance should be increased to four seconds.

• A. Three seconds
• B. Two seconds
• C. Four seconds
• D. Six seconds

Answer: (C)

When conditions are adverse, you need more space to stop safely because traction is reduced and braking distances lengthen. The four-second following distance gives you enough time to react to a hazard and come to a stop without closing in on the vehicle ahead too quickly. To check your distance, pick a fixed object on the road and start counting seconds as the rear bumper of the car in front passes the object; you should still be counting four seconds before you reach that same object. In normal, dry conditions you might use a shorter gap, but rain, snow, ice, fog, or other reduced visibility require that extra second to stay safe. This extra space also helps when following larger vehicles or driving on hills or curves, where stopping distances can be longer.